1. School of Electric Power Engineering, South China University of Technology, Guangzhou 510640; 2. Guangdong Provincial Key Laboratory of Intelligent Operation and Control for New Energy Power System, Guangzhou 510663
Abstract:The operating characteristics of power system are closely related to the strength of the receiver AC network, and the short-circuit ratio based on the conventional DC system is one of the important indicators to measure the strength of the receiver AC network. In order to consider the influence of VSC-HVDC in hybrid multi-feed system on the calculation of short-circuit ratio index, based on the definition of short circuit ratio, this paper studies the relationship between VSC-HVDC and short circuit current and multi-feed interaction factor from two aspects of short-circuit capacity and equivalent DC power, respectively. Furthermore, a method for calculating the short-circuit ratio index of the hybrid multi-infeed system considering VSC-HVDC is proposed. Finally, the accuracy of this method in calculating the short-circuit ratio of the system with VSC-HVDC is verified by the simulation of the multi-feed DC system model and the actual large system.